鉱物処理・環境・リサイクル

[3K62201-05-02] Recovery of phosphate from Sewage Sludge Ash using a leaching/neutralization process.

○Mauricio Cordova Udaeta¹, Josiane Ponou¹, Gjergj Dodbiba¹ (1. The University of Tokyo)

Keywords:Phosphate, Leaching, Sewage Sludge Ash, Neutralization

Phosphorus is a valuable resource, with some estimates predicting scarcity to come around the year 2050. Currently, Sewage Sludge Ash (SSA) is underdeveloped as a source for phosphate since phosphorus in SSA is usually present alongside heavy metals. This research is focused on the leaching of phosphorus from SSA using mineral acids and the posterior recrystallization of phosphate-bearing species in the form of calcium phosphates, which can have many applications depending on their purity and their structure. For this purpose, three different SSAs were studied and the conditions maximizing the amount of phosphorus in the leachate were determined. On the other hand, the neutralization process was carried out using NaOH showing that it is possible to crystallize calcium phosphates in a straightforward manner.